U.S. patent application number 14/899963 was filed with the patent office on 2016-05-19 for element for cooling the air of a motor vehicle.
The applicant listed for this patent is VALEO SYSTEMES THERMIQUES. Invention is credited to Kamel Azzouz, Georges De Pelsemaeker.
Application Number | 20160137020 14/899963 |
Document ID | / |
Family ID | 49212876 |
Filed Date | 2016-05-19 |
United States Patent
Application |
20160137020 |
Kind Code |
A1 |
De Pelsemaeker; Georges ; et
al. |
May 19, 2016 |
Element For Cooling The Air Of A Motor Vehicle
Abstract
The present invention relates to an element for cooling the air
in a motor vehicle, comprising a composite phase-change material
(40) made of at least one first material which is a phase-change
material (42) and one second material (44) of which the structure
forms a support matrix for said phase-change material (42), said
composite phase-change material (40) being covered with a
heat-conducting protective layer (46).
Inventors: |
De Pelsemaeker; Georges;
(Poigny-la-foret, FR) ; Azzouz; Kamel; (Paris,
FR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
VALEO SYSTEMES THERMIQUES |
Le Mesnil Saint Denis |
|
FR |
|
|
Family ID: |
49212876 |
Appl. No.: |
14/899963 |
Filed: |
June 16, 2014 |
PCT Filed: |
June 16, 2014 |
PCT NO: |
PCT/EP2014/062547 |
371 Date: |
December 18, 2015 |
Current U.S.
Class: |
62/430 ;
165/104.17; 62/244 |
Current CPC
Class: |
F28D 20/02 20130101;
B60H 1/005 20130101 |
International
Class: |
B60H 1/00 20060101
B60H001/00; F28D 20/02 20060101 F28D020/02 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 20, 2013 |
FR |
1355815 |
Claims
1. An element for cooling the air in a motor vehicle, comprising a
composite phase-change material (40) made of at least one first
material which is a phase-change material (42) and at least one
second material (44) of which the structure forms a support matrix
for said phase-change material (42), wherein said second material
(40) is covered with a heat-conducting protective layer (46).
2. An element according to claim 1, wherein said protective layer
(46) is a carbon-fiber layer.
3. An element according to claim 1, wherein said protective layer
(46) is an oleophobic and hydrophobic surface treatment having
organic/inorganic hybrid nanoparticles.
4. An element according to claim 1, wherein said protective layer
(46) is a metal film having high thermal conductivity.
5. An element according to claim 1, wherein said protective layer
(46) is an evaporative layer of a heat-conducting polymer.
6. An element according to claim 1, wherein said composite
phase-change material (40) comprises at least one rigid structural
reinforcement (48) therewithin.
7. An element according to claim 6, wherein said rigid structural
reinforcement (48) is a metal framework.
8. An element according to claim 6, wherein said rigid structural
reinforcement (48) is a plastic framework.
9. An air-conditioning device (1) for a motor vehicle, comprising
an air-conditioning loop which comprises a first heat exchanger
(12) that is in contact with the outside air and a second heat
exchanger (16) that is placed in an air-conditioning housing (2),
wherein said air-conditioning device (1) comprises at least one
element for cooling the air according to claim 1, said element
being placed in a region of an air diffuser (32) in the passenger
compartment.
10. An air-conditioning device (1) according to claim 9, wherein at
least one element for cooling the air forms a diffusion grating
(34) at an outlet of the air diffuser (32) in the passenger
compartment.
11. An air-conditioning device (1) according to claim 9, wherein at
least one element for cooling the air forms flaps (36) for
orienting and/or closing off the air flow entering the passenger
compartment.
12. An air-conditioning device (1) according to claim 10, wherein
at least one element for cooling the air forms flaps (36) for
orienting and/or closing off the air flow entering the passenger
compartment.
13. An element according to claim 2, wherein said composite
phase-change material (40) comprises at least one rigid structural
reinforcement (48) therewithin.
14. An element according to claim 3, wherein said composite
phase-change material (40) comprises at least one rigid structural
reinforcement (48) therewithin.
Description
[0001] The present invention relates to an element for cooling the
air in a motor vehicle, and more particularly to an element in the
region of an air-conditioning device in a motor vehicle comprising
a composite phase-change material.
[0002] Air-conditioning devices for motor vehicles generally
comprise an air-conditioning loop in which a heat-transfer fluid
circulates. The air-conditioning loop in particular comprises a
compressor, a first heat exchanger, an expansion valve and a second
heat exchanger that is placed in a duct for the inlet of air from
the passenger compartment.
[0003] In an air-conditioning mode, the air-conditioning loop
allows the air intended for the passenger compartment to be cooled
when the first heat exchanger acts as the condenser and the second
heat exchanger acts as the evaporator. In this configuration, the
heat energy removed by the second heat exchanger from the air
intended for the passenger compartment is released by condensation
in the region of the first heat exchanger.
[0004] In the case of what is known as a reversible
air-conditioning device, the air intended for the passenger
compartment can be heated by passing through the air-conditioning
loop in heat-pump mode. In this mode, the functions of the first
and second heat exchangers are reversed. The first heat exchanger
thus acts as the evaporator, removing heat energy from the outside
air. Said heat energy is then released in the region of the second
heat exchanger, which acts as the condenser and thus heats the air
intended for the passenger compartment.
[0005] Nevertheless, in motor vehicles equipped with an alternator
starter for implementing a device for automatically stopping and
restarting the engine, stopping the engine at traffic lights or at
a stop sign causes the compressor in the air-conditioning loop to
stop operating and therefore causes said air-conditioning loop to
stop operating.
[0006] In order to prolong the cooling of the air intended for the
passenger compartment in air-conditioning mode, integrating an
element comprising a composite phase-change material is known. When
the air-conditioning loop is in operation, the composite
phase-change material, like the air intended for the passenger
compartment, yields the heat energy to the heat-transfer fluid
while passing into the solid state. When the air-conditioning loop
is stopped, the air intended for the passenger compartment
circulating in contact with the phase-change material is cooled by
said phase-change material, which takes heat energy therefrom while
passing into the liquid phase.
[0007] The composite phase-change material comprises at least one
first material which is a phase-change material and one second
material of which the structure forms a support matrix for said
phase-change material. The composite phase-change material is such
that, owing to its composite structure, it maintains a rigid
structure whether the phase-change material is in a solid or liquid
state.
[0008] However, the use of a composite phase-change material may
pose problems relating to durability. In fact, through use, the
phase-change material present in its support matrix may reduce, for
example by evaporation or by flow. Over time, this therefore leads
to a reduction in the efficiency of said composite phase-change
material.
[0009] One of the objects of the invention is therefore to propose
an element for cooling the air comprising a composite phase-change
material that is durable over time and an air-conditioning device
for a motor vehicle which overcome at least some of the drawbacks
of the prior art.
[0010] The present invention therefore relates to an element for
cooling the air in a motor vehicle, comprising a composite
phase-change material made of at least one first material which is
a phase-change material and one second material of which the
structure forms a support matrix for said phase-change material,
said composite phase-change material being covered with a
heat-conducting protective layer.
[0011] The fact that the composite phase-change material is covered
with a heat-conducting protective layer prevents the phase-change
material from escaping, either by flow or by evaporation. In
addition, the fact that the protective layer is heat-conducting
allows good heat exchange to be maintained between the air flow
that passes in contact with the composite phase-change material and
the phase-change material.
[0012] According to one aspect of the invention, the protective
layer is an oleophobic and hydrophobic surface treatment having
organic/inorganic hybrid nanoparticles.
[0013] According to another aspect of the invention, the protective
layer is a metal film having high thermal conductivity.
[0014] According to another aspect of the invention, the protective
layer is an evaporative layer of heat-conducting polymer.
[0015] According to another aspect of the invention, the composite
phase-change material comprises at least one rigid structural
reinforcement therewithin.
[0016] According to another aspect of the invention, the rigid
structural reinforcement is a metal framework.
[0017] According to another aspect of the invention, the rigid
structural reinforcement is a plastics framework.
[0018] The present invention also relates to an air-conditioning
device for a motor vehicle, comprising an air-conditioning loop
which comprises a first heat exchanger that is in contact with the
outside air and a second heat exchanger that is placed in an
air-conditioning housing, characterised in that it comprises at
least one element for cooling the air as described above, said
element being placed in the region of the air diffuser in the
passenger compartment.
[0019] According to one aspect of the air-conditioning device
according to the invention, at least one element for cooling the
air forms a diffusion grating at the outlet of the air diffuser in
the passenger compartment.
[0020] According to another aspect of the air-conditioning device
according to the invention, at least one element for cooling the
air forms flaps for orienting and/or closing off the air flow
entering the passenger compartment.
[0021] Other features and advantages of the invention will emerge
more clearly upon reading the following description, which is given
by way of an illustrative and non-limiting example, and from the
accompanying drawings, in which:
[0022] FIG. 1 is a schematic view of an air-conditioning device for
a motor vehicle according to a first embodiment,
[0023] FIGS. 2a and 2b are schematic sectional views of the
structure of the composite phase-change material,
[0024] FIG. 3 is a schematic view of an air-conditioning device for
a motor vehicle according to a second embodiment,
[0025] FIG. 4 is a schematic view of an air-conditioning device for
a motor vehicle according to a third embodiment,
[0026] FIG. 5 is a schematic view of an air-conditioning device for
a motor vehicle according to a fourth embodiment,
[0027] FIG. 6 is a schematic view of an air-conditioning device for
a motor vehicle according to a fifth embodiment, and
[0028] FIG. 7 is a perspective exploded view of an air diffuser in
the passenger compartment.
[0029] In the various figures, identical elements bear the same
reference numerals.
[0030] FIG. 1 is a schematic view of an air-conditioning device 1.
Said air-conditioning device 1 comprises an air-conditioning loop
in which a heat-transfer fluid circulates, and comprises a first
heat exchanger 12, an expansion valve 14, a second heat exchanger
16 and a compressor 10.
[0031] The first heat exchanger 12 may be placed in contact with
the air outside the vehicle, for example in the region of the front
surface. Said first heat exchanger 12 may in particular be coupled
to a fan 18 that allows the outside air to pass through said heat
exchanger, if the motor vehicle is moving at low speed or has
stopped. The second heat exchanger 16 is in turn placed within an
air-conditioning housing 2. The compressor 10 is placed at the
outlet of the second heat exchanger 16 and the expansion valve 14
is placed at the inlet of said heat exchanger. When the
air-conditioning loop is in air-conditioning mode and is cooling
the air intended for the passenger compartment, the first heat
exchanger 12 is a condenser which yields the heat energy to the air
in order to allow the heat-transfer fluid to pass from a gaseous
phase to a liquid phase and the second heat exchanger 16 is an
evaporator which captures the heat energy of the air intended for
the passenger compartment in order to allow the heat-transfer fluid
to pass from a liquid phase to a gaseous phase.
[0032] The air-conditioning housing 2 in turn comprises a mixing
chamber 26 and air-distribution ducts 30A, 30B, 30C. A fan 22 may
also be placed upstream of the air-conditioning housing 2 in order
to propel the air through said air-conditioning housing 2.
[0033] The air intended for the passenger compartment is propelled
by the fan 22, passes through the second heat exchanger 16 and
enters the mixing chamber 26. The entry of the air in said mixing
chamber 26 is controlled and regulated by a mixing flap 24. The
orientation of the mixing flap 24 makes it possible to guide the
air intended for the passenger compartment either directly towards
the distribution ducts, the air being cold in this case, or indeed
through a heater 32, for example an additional electrical heating
device having a positive temperature coefficient, the air being
heated in this case. There is also an intermediate position, in
which the air passes on either side of the mixing flap 24, and this
allows cold air to be mixed with heated air in the mixing chamber
26. From the mixing chamber, the air intended for the passenger
compartment is distributed by means of closure flaps 28 to the
regions of the passenger compartment via the air-distribution ducts
30A, 30B and 30C. For example, the air-distribution duct 30A guides
the air towards the air outlets below the windscreen, the
air-distribution duct 30B guides the air towards the outlets on the
dashboard and the air-distribution duct 30C guides the air towards
the air outlets under the dashboard in the foot well region.
[0034] The air-conditioning housing 2 further comprises at least
one element for cooling the air in the vehicle. This element
comprises a composite phase-change material 40, the structure of
which is shown in FIGS. 2a and 2b. Said composite phase-change
material 40 is made of at least one first material which is a
phase-change material 42 and one second material 44 of which the
structure forms a support matrix for said phase-change material.
The composite phase-change material 40 is such that, owing to its
composite structure, it maintains a rigid structure whether the
phase-change material 42 is in the solid or liquid state.
[0035] The use of a composite phase-change material 40 allows
increased thermal conductivity to be ensured compared with a
phase-change material integrated into the second heat exchanger 16,
and also allows good mechanical strength to be ensured.
[0036] The composite phase-change material 40 is covered with a
heat-conducting protective layer 46 that prevents the phase-change
material 42 from escaping, either by flow or by evaporation. The
fact that the protective layer 46 is heat-conducting allows good
heat exchange to be maintained between the air flow that passes in
contact with the composite phase-change material 40 and the
phase-change material 42. In order to maintain good thermal
conduction between the outside surroundings and the composite
phase-change material 40, the protective layer 46 has a thickness
of from 0 to 100 .mu.m.
[0037] The heat-conducting protective layer 46 may in particular
be: [0038] a carbon-fibre layer, [0039] an oleophobic and
hydrophobic surface treatment having organic/inorganic hybrid
nanoparticles, [0040] a metal film having high thermal
conductivity, or [0041] an evaporative layer of heat-conducting
polymer.
[0042] A protective layer 46 which is in the form of a carbon-fibre
layer or a metal film having high thermal conductivity in
particular has a thickness that is greater than or equal to 20
.mu.m, whereas a protective layer 46 which is in the form of a
surface treatment or an evaporative layer of heat-conducting
polymer has a thickness of less than 20 .mu.m.
[0043] A thick protective layer 46 has lower thermal conduction but
greater protective potential, and conversely, a thinner protective
layer has better thermal conduction but lower protective potential.
Therefore, the choice of the type of protective layer 46 is
dependent on the placement of the composite phase-change material
40 within the air-conditioning device 1.
[0044] The phase-change material 42 used in the composite
phase-change material 40 may be, in particular, an organic or
inorganic phase-change material of plant or other origin. It
preferably has a melting temperature of between 9 and 13.degree. C.
In addition, in order to ensure a high capacity for energy storage
and therefore for removing heat from the air intended for the
passenger compartment, said phase-change material advantageously
has a latent heat of between 100 and 300 KJ/kg.
[0045] The second material 44 that forms the support matrix for the
phase-change material 42 within the composite phase-change material
40 may be a matrix of carbon capillary fibres or polymer capillary
fibres.
[0046] As shown in FIG. 2b, the composite phase-change material 40
may also comprise at least one rigid structural reinforcement 48
therewithin. This rigid structural reinforcement 48 gives the
composite phase-change material 40 better mechanical strength. The
rigid structural reinforcement 48 may be, for example, a metal
framework or a plastics framework surrounded by the composite
phase-change material 40.
[0047] According to a first embodiment of the invention shown in
FIG. 1, the element for cooling the air in the vehicle comprising
the composite phase-change material 40 surrounds the second heat
exchanger 16 at least in part. Therefore, when the air-conditioning
loop is stopped, the air intended for the passenger compartment,
which is passing through the heat exchanger, continues to be cooled
due to the transfer of heat energy between the air and the second
heat exchanger 16. Instead of being removed by the heat-transfer
fluid, this heat energy is absorbed by the composite phase-change
material 40, wherein the composite phase-change material passes
from a solid to a liquid state.
[0048] According to a variant of this first embodiment, the
composite phase-change material 40 is used as a material for
producing the support for the second heat exchanger 16.
[0049] This configuration around the second heat exchanger 16 in
particular allows the space required for integrating the composite
phase-change material 40 into the air-conditioning housing 2 to be
limited.
[0050] The element for cooling the air in the vehicle comprising
the composite phase-change material 40 may also be placed
downstream of the second heat exchanger 16 within the air-inlet
duct 2, and thus may be in direct contact with the air intended for
the passenger compartment and therefore may efficiently exchange
the heat energy therewith and therefore improve comfort for the
user if the air-conditioning loop is stopped. For this purpose, the
composite phase-change material 40 is advantageously placed
downstream of the second heat exchanger 16.
[0051] According to a second embodiment, shown in FIG. 3, the
composite phase-change material 40 is placed between the second
heat exchanger 16 and the mixing and redistribution chamber 26.
[0052] According to a third embodiment, shown in FIG. 4, the
element for cooling the air in the vehicle comprising the composite
phase-change material 40 is placed within the air-distribution
conduits 30A, 30B, 30C. This allows the space required for the
composite phase-change material 40 in the air-conditioning housing
to be limited.
[0053] According to a fourth embodiment, shown in FIG. 5, the
element for cooling the air in the vehicle comprising the composite
phase-change material 40 is integrated into the closure flaps 28.
This makes it possible to limit the space required for the
composite phase-change material 40 in the air-conditioning housing
2 and limits the disturbances to the air flow.
[0054] The composite phase-change material 40 may advantageously
form said closure flaps 28 for ease of manufacture and for the
purposes of economy.
[0055] According to a fifth embodiment, shown in FIG. 6, the
element for cooling the air in the vehicle comprising the composite
phase-change material 40 is integrated into the same wall of the
air-conditioning housing 2. In the same way, this makes it possible
to limit the space required for the composite phase-change material
40 in the air-conditioning housing 2 and limits the disturbances to
the air flow.
[0056] The composite phase-change material 40 may also, and
advantageously, form the wall of the air-conditioning housing 2,
again for ease of manufacture and for the purposes of economy.
[0057] According to a sixth embodiment, shown in FIG. 7, the
element for cooling the air in the vehicle comprising the composite
phase-change material 40 is placed in the region of the air
diffuser 32 in the passenger compartment. The phase-change material
40 may thus form a diffusion grating 34 at the outlet of the air
diffuser 32 in the passenger compartment or may form flaps 36 for
orienting and/or closing off the air flow entering the passenger
compartment.
[0058] Therefore, it is clear that by applying a heat-conducting
protective layer, the composite phase-change material becomes more
durable because the phase-change material that it contains remains
therewithin.
* * * * *